# Homework Help: Using thermistors as thermometers - Coursework

1. Mar 3, 2009

### rit

For my as Physics Sensing Coursework,

I have chosen to do it on 'using thermistors as simple thermometers'

Can someone please help me on how to set up the circuit. And how i do i get and use the measurements.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

2. Mar 4, 2009

### rit

Help me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

3. Mar 4, 2009

### turin

Read the forum rules!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

4. Mar 4, 2009

### rit

i have tried myself, but i couldnt do it,

and im not allowed to ask teachers, because ill lose lots of marks.

You dont have to do it for me, just give me hints!!!!!

5. Mar 4, 2009

### turin

If you promise to stop using so many exclamation marks. It makes your posts difficult to read.

First question: What is "the circuit"?

Second question: Did you do a search on thermistors, thermometers, etc.?

6. Mar 4, 2009

### rit

sorry,

1) when i say circuit, i mean how to set up, e.g, what i need, i got a thermister, voltmeter,amp meter, powerpack. (dont worry about changing the temp. i got that covered.(putting water in a microwave))

2) yh, i have done my research, i got no problem with that.

7. Mar 5, 2009

### rit

I have done my experiment (well half of it, i still have to get the second set of results)

in my results i got the, resistance of the thermister at different tempertures (from the Amp meter)

e.g. at 80 c (temperture) the resistance was 0.96 k ohms.

the thing i dont get is how i use my results.

8. Mar 5, 2009

### turin

If you're allowed to include the ohmmeter in your circuit, then I'd say you're pretty much done. All you lack is a lookup table.

9. Mar 5, 2009

### rit

whats a lookup table

10. Mar 5, 2009

### turin

A literal table. For instance, I have seen a piece of equipment that had a sticker stuck to the side with two columns of numbers: one column was the resistance value and the other column was the temperature. Alternatively (and my personal preference), a lookup table could be in the form of a formula for temperature in terms of resistance. There is a theoretical formula (that you probably found in your research) for the temperature dependence of the resistance, which has at least one unknown parameter. You can fit your experimental data to this formula to extract the parameter(s).

11. Mar 6, 2009

Thanks